Wall tie

Abstract: A wall tie for use in securing a wall to a support, the wall tie being characterized by resilient grip means for attaching the wall tie to the support. In one embodiment, the grip means comprises first and second jaws (12, 14) resiliently biased towards one another such that, in use, the support is gripped between the jaws (12, 14).

Description: This invention relates to a wall tie, more particularly to a wall tie for use in securing a wall to a parallel flange of a support member, for example a steel column or wind post. Wall ties are commonly used to secure brick or block built leaves of cavity walls to one another or to secure walls constructed of building bricks or blocks to support structures in order to strengthen the walls. One problem associated with wall ties for securing walls to support structures is that the thickness and/or sectional shape of the support structures is not uniform, and hence a variety of wall ties must be provided so that the correct type of wall tie can be used at a particular location. It is inconvenient to stock a large range of wall ties, and it is an object of the invention to provide a wall tie in which this disadvantage is reduced. A wall tie for use in securing a wall to a support is known from AU-B-518 132. According to the present invention there is provided a wall tie for use in securing a wall to a support, the wall tie comprising a pair of limbs one of the limbs being arranged to counter forces tending to move the wall away from the support, the other limb being arranged to counter forces tending to move the wall towards the support characterised in that, each limb is carrying a respective jaw, the jaws being resiliently biased towards one another such that, in use, the support is gripped therebetween. The provision of resilient grip means allows a standard wall tie to be used in conjunction with supports of varying thicknesses and section. Preferably the wall tie is defined by a metal wire member in the form of a loop, the ends of the member extending generally perpendicular to the length of the tie adjacent one another and defining the first and second jaws respectively, the first and second jaws preferably extending generally parallel to one another. The loop is preferably of generally rectangular shape, the jaws being provided at a first short side thereof. Each of the long sides of the loop is preferably shaped so as to provide a point from which water can drip, in use. Preferably, the side opposite said first short side is of length greater than said first short side, the wire being smoothly curved at the junction of said side opposite said first short side and a long side to displace part of the long side outwardly. At least one of said jaws of the member is preferably reinforced. Such reinforcing may be achieved by shaping the member so that the end region thereof doubles back upon itself. Preferably one end of the member defining one of the jaws is bent around that region of the opposite long limb of the member which terminates in the other jaw, such that said one jaw comprises a pair of parallel elements. Preferably said wire is stainless steel; galvanised steel; or mild steel and may be provided within a plastics sleeve. The invention will further be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a wall tie according to a first embodiment of the invention; Figure 2 is a perspective view of a modification to the wall tie of Figure 1; Figure 3 is a perspective view of a further modification; Figure 4 is a perspective view of the embodiment of Figure 1, in use; Figure 5 is a plan view of a second embodiment; and Figure 6 is a cross-sectional view along the line X-X of Figure 5. The wall tie illustrated in Figures 1 and 4 comprises a length of stainless steel wire of 3.7 mm diameter shaped so as to form a generally planar rectangular loop 10, the end regions 12, 14 of the length of wire overlapping generally parallel to each other along a first short side 16 of the rectangular loop 10. The loop 10 has an opposite short side 22 and generally parallel long sides 18 and 20, the end region 12 being integral with the end of the long side 20 and extending perpendicular thereto. The end region 12 of the wire is folded so as to double back upon itself to form a U-shaped region through which the end of the long side 18 passes before becoming the end region 14, the U-shaped region extending across the complete width of the first short side 16. The second end region 14 of the wire is also folded back upon itself, the folded back wire also extending across the full width of the first short side 16 and also extending along part of the length of a first long side 18 of the loop 10 through the U-shape of the end region 12. Whereas the region 12 is an open U-shape, folded back part of the region 14 is not open, the runs of the wire being in contact. The second long side 20 extends generally parallel to the first long side 18, separated therefrom by a distance generally equal to the length of the first short side 16. The second short side 22 is longer than the first short side 16, the wire being smoothly curved at the junction between the second short side 22 and the second long side 20 to displace part of the side 20 outwardly to allow for the increased length of the second short side 22. In use, during construction of a wall, the wall tie is attached to a support including a flange 24 extending generally perpendicularly to the plane of the wall by inserting the flange 24 between the ends 12, 14 of the wire. The flange 24 illustrated in Figure 4 is of generally rectangular cross section, the wall tie being suitable, by virtue of its resilience, for use with supports including flanges of a variety of thicknesses and a variety of cross sections, for example flanges of tapering cross section. The action of attaching the wall tie to the flange 24 in this manner spreads the end regions 12, 14 of the wire which act as cooperating jaws engaging opposite faces of the flange, the resilience of the wire resulting in the flange 24 being gripped therebetween. The other end of the wall tie is embedded in the mortar of the wall before an upper course of building bricks or blocks is positioned thereon. It will be understood that once the mortar has set, forces tending to move the wall towards the support result in the limb of the wall tie including the second long side 20 experiencing a compressive load which is transmitted to the support by means of the first end region 12 of the member, and forces tending to move the wall away from the support result in the limb of the wall tie including the first long side 18 being put under tension, this force being transmitted to the support through the second end region 14 of the member. The embodiments shown in Figures 2 and 3 are modifications of the embodiment described above. The first and second ends 12, 14 of the embodiment shown in Figure 2 are not folded back upon themselves, this construction being a very simple construction. This construction is particularly suitable for use where the loading to be applied to the wall tie is likely to be small. It has been found that when larger loads are applied to the wall tie the loop may tend to buckle allowing the jaws 12, 14 to slide off the flange. The use of a U-shape for the jaw or end region 12 with the long side 18 extending therethrough effects a restraining action resisting such buckling and moreover spreads compressive loadings over a greater area of the flange further stabilizing the tie. The reinforcement of the jaw 14 by folding back (Figures 1 and 4) increases the resistance of the jaw 14 to straightening when the long side 18 is in tension. The wall ties illustrated in Figures 2 and 3 are used in exactly the same manner as that illustrated in Figures 1 and 4. In each of the illustrated wall ties the long sides 18, 20 are preferably provided, at a point which will lie in the cavity between the wall and the flange 24, with a downward kink to provide a drip formation for promoting the collection and shedding of water drops in known manner. The support including the flange 24 can be any of a variety of known structures including a steel column of H or I section, a channel member, an angle section and various known wind post constructions. The embodiment illustrated in Figures 5 and 6 is similar to the first embodiment and the modifications thereto described above, and like reference numerals in the following description will be used to denote parts similar to those of the first embodiment and the described modifications. The wall tie of Figures 5 and 6 comprises a length of 4.85 mm diameter stainless steel wire bent so as to form a generally rectangular loop 10, the end regions 12, 14 of the wire overlapping one another at the corner between a short side 16 and a long side 20 of the loop 10. The loop 10 has a second long side 18 parallel to the side 20, the ends of the long sides 18, 20 furthest from the end regions 12, 14 being interconnected by an integral part circular region 26 of diameter greater than the separation of the long sides 18, 20. A downwardly directed kink 34 is provided in each of the long sides 18, 20 to define a pair of points at which water collects and from which water drips in order to prevent the flow of water along the full length of the long sides 18, 20. The kink 34 is shown clearly in Figure 6. The end region 12 is folded back upon itself defining a generally U-shaped U-shaped region, the long side 20 extending between the arms of the region. The end region 14 is shaped so as to include a first region 28 at the free end thereof extending generally parallel to the end region 12, a second region 30 extending away from the end region 12, and a third, curved region 32 at the junction between the end region 14 of the long side 20. In use, the wall tie is attached to the support structure of the construction by introducing part of the support structure between the end region 12 and the first region 28 of the end region 14, these regions of the wall tie being resiliently biased towards one another to grip the support structure. The part circular region 26 together with the ends of the long sides 18, 20 is positioned in the mortar on top of a course of bricks or other building blocks, and a further course of bricks or blocks are positioned on top of the mortar. Once the mortar has hardened, the wall tie acts to prevent movement of the leaf wall constructed of bricks or blocks towards or away from the support structure, movement of the leaf away from the support structure being countered by the long side 20 becoming under tension whilst movement of the leaf towards the support structure is countered by the long side 18 being compressed. It has been found that when the long side 18 is compressed, there is a tendency for the long side 18 to flex away from the long side 20 and in this embodiment, such flexing is restricted by the end region 12 being bent around the long side 20. When the long side 20 becomes under tension, there is a tendency for the end region 14 to bend towards the axis of the long side 20, and the provision of the second and third regions 30, 32 of the end region 14 in this embodiment tends to reduce such bending. In the second embodiment, the second region 30 of the end region 14 extends generally parallel to the long side 20. It is envisaged that the second region 30 may extend away from the end region 12 at an angle of approximately 30°, and that the end region 14 of the wall tie of the first embodiment and its modification may also be provided with the above described first, second and third regions 28, 30, 32. In addition, such embodiments may also be provided with the part circular region 26 interconnecting the long sides 18, 20 instead of the second short side described above.

Claims: A wall tie for use in securing a wall to a support, the wall tie comprising a pair of limbs (18, 20) one of the limbs (18) being arranged to counter forces tending to move the wall away from the support, the other limb (20) being arranged to counter forces tending to move the wall towards the support characterised in that, each limb (18, 20) is carrying a respective jaw (12, 14), the jaws (12, 14) being resiliently biased towards one another such that, in use, the support is gripped therebetween. A wall tie as claimed in Claim 1, characterized in that the wall tie is defined by a metal wire member in the form of a loop (10), the ends of the member extending generally perpendicular to the length of the tie adjacent one another and defining the first and second jaws (12, 14) respectively. A wall tie as claimed in Claim 2, characterized in that the first and second jaws extend generally parallel to one another. A wall tie as claimed in Claim 2 or Claim 3, characterized in that the loop is of generally rectangular shape, the jaws (12, 14) being provided at a first short side (16) thereof. A wall tie as claimed in Claim 4, wherein the side opposite said first short side (16) is of length greater than said first short side (16), the wire being smoothly curved at the junction of said side opposite said first short side (16) and a long side (20) to displace part of the long side (20) outwardly. A wall tie as claimed in Claim 2 or Claim 3, wherein the part of the loop opposite said first and second jaws (12, 14) is of part circular form. A wall tie as claimed in Claim 4, 5 or 6, characterized in that each of the long sides (18, 20) of the loop (10) is shaped so as to provide a point from which water can drip, in use. A wall tie as claimed in any one of Claims 1 to 7, characterized in that at least one of said jaws (12, 14) is reinforced. A wall tie as claimed in Claim 8, characterized in that the at least one jaw (12, 14) is reinforced by shaping the member so that the end region thereof doubles back upon itself. A wall tie as claimed in any one of Claims 1 to 9, characterized in that the end of the member defining one of the jaws (12) is bent around that region of the opposite limb of the member which terminates in the other jaw (14), such that said one jaw (12) comprises a pair of parallel elements. A wall tie as claimed in any one of the preceding claims, characterized in that the end of the member defining one of the jaws (14) comprises a first region (28) extending generally parallel to the other jaw (12), and a second region (30) extend away from said other jaw (12).

Inventors: BURNS ROY JOHN, BURNS, ROY JOHN
Applicants: METSEC PLC
Application year: 1994
Main classification: E04B1
IPC codes: E04B1